Quentin, A.G., CSIRO Land and Water, Private Bag 12, Hobart, TAS, Australia, Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, Australia
Pinkard, E.A., CSIRO Land and Water, Private Bag 12, Hobart, TAS, Australia
Ryan, M.G., Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, Australia, Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, United States, USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO, United States
Tissue, D.T., Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, Australia
Baggett, L.S., USDA Forest Service, Rocky Mountain Research Station, Fort Collins, CO, United States
Adams, H.D., Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
Maillard, P., INRA, UMR 1137, Ecologie et Ecophysiologie Forestières, Centre de Nancy, Champenoux, France
Marchand, J., INRA, UMR 1137, Ecologie et Ecophysiologie Forestières, Plateforme Technique d'Ecologie Fonctionnelle (OC 081) Centre de Nancy, Champenoux, France
Landhäusser, S.M., Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
Lacointe, A., INRA, UMR 0547 PIAF, Clermont-Ferrand, France, Clermont Université, Université Blaise Pascal, UMR 0547 PIAF, Clermont-Ferrand, France
Gibon, Y., UMR1332, Biologie du Fruit et Pathologie, INRA, Bordeaux University, 71 avenue Edouard Bourlaux, Villenave d'Ornon, France, Plateforme Métabolome du Centre de Génomique Fonctionnelle Bordeaux, MetaboHUB, IBVM, Centre INRA, 71 avenue Edouard Bourlaux, Villenave d'Ornon, France
Anderegg, W.R.L., Princeton Environmental Institute, Princeton University, Princeton, NJ, United States
Asao, S., Natural Resources Ecology Laboratory, Colorado State University, Fort Collins, CO, United States, Graduate Degree Program in Ecology, Colorado State University, Fort Collins, CO, United States
Atkin, O.K., Division of Plant Sciences, Research School of Biology, Australian National University, Building 46, Canberra, ACT, Australia, ARC Centre of Excellence in Plant Energy Biology, Australian National University, Canberra, ACT, Australia
Bonhomme, M., INRA, UMR 0547 PIAF, Clermont-Ferrand, France, Clermont Université, Université Blaise Pascal, UMR 0547 PIAF, Clermont-Ferrand, France
Claye, C., Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Private Bag 98, Hobart, TAS, Australia
Chow, P.S., Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
Clément-Vidal, A., CIRAD, UMR AGAP, Montpellier, France
Davies, N.W., Central Science Laboratory, University of Tasmania, Private Bag 74, Hobart, TAS, Australia
Dickman, L.T., Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
Dumbur, R., Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, P.O. Box 12, Rehovot, Israel
Ellsworth, D.S., Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, Australia
Falk, K., Department of Forest Ecosystems and Society, Oregon State University, Corvallis, OR, United States
Galiano, L., Swiss Federal Research Institute WSL, Birmensdorf, Switzerland, Institute of Hydrology, Freiburg University, Fahnenbergplatz, Freiburg, Germany
Grünzweig, J.M., Robert H. Smith Faculty of Agriculture, Food and Environment, Hebrew University of Jerusalem, P.O. Box 12, Rehovot, Israel
Hartmann, H., Max Planck Institute for Biogeochemistry, Hans-Knöll Str. 10, Jena, Germany
Hoch, G., Department of Environmental Sciences - Botany, University of Basel, Schönbeinstrasse 6, Basel, Switzerland
Hood, S., Division of Biological Sciences, University of Montana, Missoula, MT, United States
Jones, J.E., Tasmanian Institute of Agriculture, School of Land and Food, University of Tasmania, Private Bag 98, Hobart, TAS, Australia
Koike, T., Silviculture and Forest Ecological Studies, Hokkaido University Sapporo, Hokkaido, Japan
Kuhlmann, I., Max Planck Institute for Biogeochemistry, Hans-Knöll Str. 10, Jena, Germany
Lloret, F., CREAF, Cerdanyola del Vallès, Barcelona, Spain, Universidad Autònoma Barcelona, Cerdanyola del Vallès, Barcelona, Spain
Maestro, M., Instituto Pirenaico de Ecología (IPE-CSIC), Av. Nuestra Señora de la Victoria s/n, Jaca, Huesca, Spain
Mansfield, S.D., Department of Wood Science, University of British Columbia, Vancouver, Canada
Martínez-Vilalta, J., CREAF, Cerdanyola del Vallès, Barcelona, Spain, Universidad Autònoma Barcelona, Cerdanyola del Vallès, Barcelona, Spain
Maucourt, M., Plateforme Métabolome du Centre de Génomique Fonctionnelle Bordeaux, MetaboHUB, IBVM, Centre INRA, 71 avenue Edouard Bourlaux, Villenave d'Ornon, France, Université Bordeaux, UMR 1332, Biologie du Fruit et Pathologie, 71 avenue Edouard Bourlaux, Villenave d'Ornon, France
McDowell, N.G., Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM, United States
Moing, A., UMR1332, Biologie du Fruit et Pathologie, INRA, Bordeaux University, 71 avenue Edouard Bourlaux, Villenave d'Ornon, France, Plateforme Métabolome du Centre de Génomique Fonctionnelle Bordeaux, MetaboHUB, IBVM, Centre INRA, 71 avenue Edouard Bourlaux, Villenave d'Ornon, France
Muller, B., INRA, UMR 759 LEPSE, Montpellier, France
Nebauer, S.G., Plant Production Department, Universitat Politécnica de Valéncia, Camino de vera s.n., Valencia, Spain
Niinemets, U., Department of Plant Physiology, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu, Estonia
Palacio, S., Instituto Pirenaico de Ecología (IPE-CSIC), Av. Nuestra Señora de la Victoria s/n, Jaca, Huesca, Spain
Piper, F., Centro de Investigación en Ecosistemas de la Patagonia (CIEP), Simpson 471, Coyhaique, Chile
Raveh, E., Department of Fruit Trees Sciences, Institute of Plant Sciences, A.R.O., Gilat Research Center, D.N. Negev, Israel
Richter, A., CIRAD, UMR AGAP, Montpellier, France
Rolland, G., INRA, UMR 759 LEPSE, Montpellier, France
Rosas, T., CREAF, Cerdanyola del Vallès, Barcelona, Spain
Joanis, B.S., INRA, UMR 0547 PIAF, Clermont-Ferrand, France, Clermont Université, Université Blaise Pascal, UMR 0547 PIAF, Clermont-Ferrand, France
Sala, A., Division of Biological Sciences, University of Montana, Missoula, MT, United States
Smith, R.A., Hawkesbury Institute for the Environment, University of Western Sydney, Richmond, NSW, Australia
Sterck, F., Forest Ecology and Forest Management Group, Wageningen University, Postbox 47, Wageningen, Netherlands
Stinziano, J.R., Department of Biology, Western University, 1151 Richmond Street, London, ON, Canada
Tobias, M., Department of Plant Physiology, Estonian University of Life Sciences, Kreutzwaldi 1, Tartu, Estonia
Unda, F., Department of Wood Science, University of British Columbia, Vancouver, Canada
Watanabe, M., Institute of Agriculture, Tokyo University of Agriculture and Technology Fuchu, Tokyo, Japan
Way, D.A., Department of Biology, Western University, 1151 Richmond Street, London, ON, Canada, Nicholas School of the Environment, Duke University, Box 90328, Durham, NC, United States
Weerasinghe, L.K., Division of Plant Sciences, Research School of Biology, Australian National University, Building 46, Canberra, ACT, Australia, Faculty of Agriculture, University of Peradeniya, Peradeniya, Sri Lanka
Wild, B., Department of Microbiology and Ecosystem Science, University of Vienna, Althanstrasse 14, Vienna, Austria, Department of Earth Sciences, University of Gothenburg, Guldhedsgatan 5A, Gothenburg, Sweden
Wiley, E., Department of Renewable Resources, University of Alberta, Edmonton, AB, Canada
Woodruff, D.R., USDA Forest Service, Forestry Sciences Laboratory, Corvallis, OR, United States

Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g-1 for soluble sugars, 6-533 (mean = 94) mg g-1 for starch and 53-649 (mean = 153) mg g-1 for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R2 = 0.05-0.12 for soluble sugars, 0.10-0.33 for starch and 0.01-0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g-1 for total NSC, compared with the range of laboratory estimates of 596 mg g-1. Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41-0.91), but less so for total NSC (r = 0.45-0.84) and soluble sugars (r = 0.11-0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory may be comparable within and between laboratories, especially for starch. To obtain comparable NSC estimates, we suggest that users can either adopt the reference method given in this publication, or report estimates for a portion of samples using the reference method, and report estimates for a standard reference material. Researchers interested in NSC estimates should work to identify and adopt standard methods. © The Author 2015.